Event filter

eventFilter() — chainable builder for filtering Qubic log events by identity, contract, log type, and tick range.

eventFilter() returns a chainable builder for constructing EventFilter objects. Pass the result to subscription helpers or archive queries to narrow the event stream.

The builder is immutable: each method call returns the same builder instance after mutating internal state, so you can chain calls freely.

`eventFilter()`

import { eventFilter, LOG_TYPE } from "@qubic.org/events"
import { toIdentity } from "@qubic.org/types"

const identity = toIdentity("CFBMEMZOIDEXQAUXYYSZIURADQLAPWPMNJXQSNVQZAHYVOPYUKKJBJUCTVJL")

const filter = eventFilter()
  .forIdentity(identity)
  .ofTypes(LOG_TYPE.QU_TRANSFER, LOG_TYPE.BURNING)
  .fromTick(25_000_000)
  .build()

Returns EventFilterBuilder — see builder methods below.

Builder methods

`.forIdentity(identity)`

Restricts events to those involving the given identity (as source, destination, or owner, depending on the log type).

eventFilter().forIdentity(identity)

Parameters

Name	Type	Description
`identity`	`Identity`	Qubic identity to filter by

`.forContract(contractIndex)`

Restricts events to those emitted by the given contract.

eventFilter().forContract(9)  // Qearn contract

Parameters

Name	Type	Description
`contractIndex`	`number`	Contract index on the Qubic network

`.ofTypes(...logTypes)`

Restricts events to the specified log types. Pass multiple types to match any of them.

import { LOG_TYPE } from "@qubic.org/events"

eventFilter().ofTypes(LOG_TYPE.QU_TRANSFER, LOG_TYPE.BURNING)

When building a Bob subscription filter with .toBobFilter(), only the first log type is forwarded (Bob's WebSocket API supports one type per subscription). Use subscribeAllEvents with a broader filter when you need multiple types in a single stream.

Parameters

Name	Type	Description
`...logTypes`	`LogType[]`	One or more `LOG_TYPE` values

`.fromTick(tick)`

Restricts to events at or after the given tick.

eventFilter().fromTick(25_000_000)

`.toTick(tick)`

Restricts to events up to and including the given tick.

eventFilter().toTick(26_000_000)

`.build()`

Returns the EventFilter object. Use this with subscription helpers from @qubic.org/events.

const filter = eventFilter().forIdentity(identity).build()

for await (const event of subscribeAllEvents(bob.subscription, filter)) {
  // ...
}

Returns EventFilter

Field	Type	Description
`identity`	`Identity`	Set by `.forIdentity()`
`contractIndex`	`number`	Set by `.forContract()`
`logTypes`	`LogType[]`	Set by `.ofTypes()`
`fromTick`	`number`	Set by `.fromTick()`
`toTick`	`number`	Set by `.toTick()`

`.toBobFilter()`

Returns a BobLogFilter for direct use with bob.subscription.subscribeLogs. Only the first logType from .ofTypes() is included, since Bob's WebSocket API supports one log type per subscription filter.

const bobFilter = eventFilter()
  .forIdentity(identity)
  .ofTypes(LOG_TYPE.QU_TRANSFER)
  .toBobFilter()

for await (const event of bob.subscription.subscribeLogs(bobFilter)) {
  // raw BobLogEvent — call decodeEvent if you need typed data
}

Returns BobLogFilter

Composing a filter

import { eventFilter, LOG_TYPE, subscribeAllEvents } from "@qubic.org/events"
import { createBobClient } from "@qubic.org/bob"
import { toIdentity } from "@qubic.org/types"

const bob = createBobClient({ baseUrl: "http://localhost:40420" })

const identity = toIdentity("CFBMEMZOIDEXQAUXYYSZIURADQLAPWPMNJXQSNVQZAHYVOPYUKKJBJUCTVJL")

// Watch all transfers and burns for an identity, starting from a specific tick
const filter = eventFilter()
  .forIdentity(identity)
  .ofTypes(LOG_TYPE.QU_TRANSFER, LOG_TYPE.BURNING)
  .fromTick(25_000_000)
  .build()

for await (const event of subscribeAllEvents(bob.subscription, filter)) {
  if (event.isCatchUp) continue

  const typed = event.data

  if (typed.logType === LOG_TYPE.QU_TRANSFER) {
    console.log("Transfer:", typed.data.amount)
  } else if (typed.logType === LOG_TYPE.BURNING) {
    console.log("Burn:", typed.data.amount, "from", typed.data.source)
  }
}

Event filter

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